Refactor SHA*_file functions into a separate file. Generate them using a C macro.

src/platform/vboot_reference/tests/digest_utility.h

+/* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Utility functions for message digest functions. */
+
+#ifndef VBOOT_REFERENCE_DIGEST_UTILITY_H_
+#define VBOOT_REFERENCE_DIGEST_UTILITY_H_
+
+#include <inttypes.h>
+
+/* Returns the SHA-1 digest of data in [input_file].
+ * Caller owns the returned digest and must free it.
+ */
+uint8_t* SHA1_file(char *input_file);
+
+/* Returns the SHA-256 digest of data in [input_file].
+ * Caller owns the returned digest and must free it.
+ */
+uint8_t* SHA256_file(char *input_file);
+
+/* Returns the SHA-512 digest of data in [input_file].
+ * Caller owns the returned digest and must free it.
+ */
+uint8_t* SHA512_file(char *input_file);
+
+/* Returns the appropriate digest for the data in [input_file]
+ * based on the signature [algorithm].
+ * Caller owns the returned digest and must free it.
+ */
+uint8_t* calculate_digest(char *input_file, int algorithm);
+
+#endif  /* VBOOT_REFERENCE_DIGEST_UTILITY_H_ */